Would I be able to detect E field around magnet spinning on its axis using electroscope? I like to use electronic electroscope in setup like this:
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$\begingroup$ Why don't you try it and find out? The apparatus seems simple enough. $\endgroup$– sammy gerbilCommented Aug 28, 2016 at 11:14
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$\begingroup$ not so easy , magnet has to spin perfectly, no wobbling and orbiting, cant move in space other way than just spinning.But there should be E field or not? $\endgroup$– szuflaCommented Aug 28, 2016 at 12:14
1 Answer
I think the question is equivalent to asking whether there is B field when you have a rotating electret. Which is equivalent to two rotating surface current density. And the answer is yes, there is B field in the radial and axial direction when the thickness of the electret has a finite thickness. But for an ideal electret of zero thickness there will be no B field.
So I think for a real magnet with finite thickness, there will be E field in the radial and axial direction. But when thickness of the magnet is very small, the E field vanishes.
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$\begingroup$ yeah, any proof for that? book or something... $\endgroup$– szuflaCommented Aug 29, 2016 at 6:18
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$\begingroup$ I just tried to google "rotating magnet" and found something, for example, this: physics.stackexchange.com/questions/6581/… $\endgroup$ Commented Aug 29, 2016 at 6:51
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$\begingroup$ I have seen that, a lot of talk but no links for real experiments...also, where is earth electric field?, earth has magnet inside and rotates. $\endgroup$– szuflaCommented Aug 29, 2016 at 9:52
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$\begingroup$ I think there is such an E field, but so small in magnitude because of the small $\omega$ of the Earth. $\endgroup$ Commented Aug 29, 2016 at 9:58